The US government conducted a 2-year National Toxicology Program (NTP) study on oral consumption of whole-leaf extractextractto get, separate, or isolate a desired active ingredient of aloe vera and found clear evidence of carcinogenic activity in male and female rats, based on tumours of the large intestine. Components of aloe vera called anthraquinones are suspected to be carcinogenic when consumed orally. According to the NTP, from what is known right now there is nothing that would lead them to believe that these findings are not relevant to humans. However, more information, including how individuals use different types of aloe vera products, is needed to determine the risk to humans.

Topical aloe vera and oral aloe gel are generally well tolerated. Occasionally their use has been associated with burning, rash, and itching.

There have been a few case reports of acute hepatitis from aloe latex. However, the evidence is not definitive and the safety of aloe has not been systematically studied. Nephritis (kidney disease) and kidney failure have also been associated with ingesting high doses of aloe latex. Theoretically, aloe latex may aggravate kidney disorders.

If you have diabetes and use glucose-lowering medication, be cautious about also taking aloe by mouth because preliminary studies suggest aloe may lower blood glucose levels. If you have a kidney disorder, are taking medications or health products that may worsen electrolyte imbalance (e.g., thiazide diuretics, corticosteroids), are taking cardiaccardiacrelating to the heart medications (e.g., medications used for arrthymia), or have fecal impaction or symptoms such as abdominal pain, nausea, vomiting, or fever, talk to your health care professional before using aloe latex.

If you are experiencing abdominal pain, cramps, spasms, or diarrhea, reduce your dose of aloe latex or stop using it.

Do not take aloe latex if you have certain diseases of the gastrointestinal tract (e.g., Crohn’s disease, ulcerative colitis, appendicitis), undiagnosed rectal bleeding, abdominal pain with an unknown cause, severe dehydration, hemorrhoids or diarrhea.

Do not take aloe orally if you are pregnant or breast-feeding. Children should also not take aloe orally.

Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.